Residual Anxiety Predicts Depression Relapse in Bipolar II Depression

The effect size of venlafaxine was larger for depressive symptoms relative to lithium compared with its effect size for anxiety symptoms.

According to the results of a recent study published in the Journal of Affective Disorders, venlafaxine was more efficacious than lithium for depression and anxiety, and residual anxiety at the end of treatment was associated with depressive relapse.

Researchers used data from a randomized 12-week study of venlafaxine compared with lithium monotherapy for bipolar II depression in 129 adults followed by a 6-month continuation study in 55 adults. Symptoms of anxiety and depression were distinguished using the Hamilton Rating Scale for Depression, and the study authors evaluated the association of baseline anxiety and depression with changes in anxiety and depression over time.

Compared with lithium, venlafaxine reduced symptoms of depression (P <.001) and anxiety (P =.027). The effect size of venlafaxine was larger for depressive symptoms relative to lithium compared with its effect size for anxiety symptoms.

At the completion of the 12-week treatment, residual depression, but not residual anxiety, was more common in the lithium group than in the venlafaxine group. Moreover, residual symptoms of anxiety were strongly associated with depression relapse (odds ratio [OR], 2.05; P =.02), whereas residual depressive symptoms (OR, 1.24; P =.13) and treatment condition (OR, 0.39; P =.26) were not associated with depression relapse.

In an interview with Psychiatry Advisor, Lorenzo Lorenzo-Luaces, PhD, assistant professor at Indiana University, Bloomington, and lead author on the study, called the study results "surprising," as conventional wisdom suggests that anxiety and depression "go together." He concluded that for patients with bipolar II depression, treating the depression is "very important...but for some, it is just a start, and there are other areas of life and psychological well-being that need to be addressed."